solar intensity variability and crop spectral reflectance n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE PowerPoint Presentation
Download Presentation
SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE

Loading in 2 Seconds...

play fullscreen
1 / 12

SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE - PowerPoint PPT Presentation


  • 76 Views
  • Uploaded on

SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE. By Birehane Desta Thanks to Y.Kanke, Y. Mohammed, E. Ruto, and D. Edmonds. INTRODUCTION. The sun is the source of light intensity for passive sensors.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE' - kevyn-cobb


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
solar intensity variability and crop spectral reflectance

SOLAR INTENSITY VARIABILITY AND CROP SPECTRAL REFLECTANCE

By

Birehane Desta

Thanks to Y.Kanke, Y. Mohammed, E. Ruto, and D. Edmonds

slide2

INTRODUCTION

  • The sun is the source of light intensity for passive sensors.
  • This intensity is not always reliable and constant for crop measurement even during the overhead sun.
  • Intensity may vary(fluctuate) during; measuring two nearby plots, at different hours ,and seasons.
slide3

Sun

Atmosphere

Hydrosphere

Lithospher

Biosphere

Adopted from Robert Derveloy's photostream

  • Cloud, landscapes, and trees are the main cause for variability of incoming radiation.
slide4

OBJECTIVE

  • The objective of this presentation is to show the effect of Solar intensity variation on winter wheat spectral reflectance
slide5

MATERIALS AND METHODS

  • Spectral measurements were taken on high and low intensity days from different treatments of winter wheat(Perkins,OK) using Ocean Optics Spec 4000.
  • Based on the intensity variation within time ,white board measurements were taken untill the end of the reading.
  • The intensity were compared and the differences were considered.
  • Then reflectance was computed.
slide6

Using SAS, minimum and maximum reading were selected both from low and high intensity days and NDVI was computed.

  • Correlation analysis was employed for low and high intensity NDVI to evaluate the degree of determination (R2).
  • For some selected wave lengths, the high and the low intensity trend were compared.
r2 value from low and high reflectance ndvi
R2 value from low and high reflectance NDVI

RESULTS

  • There were no R2=1 for the NDVI from the same spot-measured at different solar intensity.
slide8

The correlation between low and high intensity- reflectance NDVI of each plot were not significant.

slide9

Plots in treatment and rep order, and reflectance trend, Perkins 2009.

Low intensity-reflectance (505,LI R min), (865,LI NIR max) and High Intensity-(505,HI R min),(865,HI NIR max) were almost had similar reflectance

slide10

Reflectance variation is higher for low intensity than high intensity.

  • High intensity variation was found with in an hour time measurements on high isolation day.
slide11

Temporal fluctuation of solar intensity resulted in biased winter wheat crop reflectance measurement when passive sensors were used.